title: delta1-piperideine-2-carboxylate reductase of Pseudomonas putida.
abstract: Pseudomonas putida metabolizes D-lysine to delta 1-piperideine-2-carboxylate and L-pipecolate. The second step of this catabolic pathway is catalyzed by delta 1-piperideine-2-carboxylate reductase. This enzyme was isolated and purified from cells grown on DL-lysine as substrate. The enzyme was very unstable, resulting in low recovery of activity and low purity after a six-step purification procedure. The enzyme had a pH optimum of 8.0 to 8.3. The Km values for delta 1-piperideine-2-carboxylate and NADPH were 0.23 and 0.13 mM, respectively. NADPH at concentrations above 0.15 mM was inhibitory to the enzyme. Delta 1-pyrroline-5-carboxylate, pyroglutamate, and NADH were poor substrates or coenzyme for delta 1-piperideine-2-carboxylate reductase. The enzyme reaction from delta 1-piperideine-2-carboxylate to L-pipecolate was irreversible. EDTA, sodium pyrophosphate, and dithiothreitol at concentrations of 1 mM protected the enzyme during storage. The enzyme was inhibited almost totally by Zn2+, Mn2+, Hg2+ Co2+, and p-chloromercuribenzoate at concentrations of 0.1 mM. The enzyme had a molecular weight of about 200,000. Both D-lysine and L-lysine were good inducers for the enzyme. Neither delta1-piperideine-2-carboxylate nor L-pipecolate was an effective inducer for the enzyme. P. putida cells grew on D-lysine only after a 5- to 8-h lag, which could be abolished by adding a supplement of 0.01% alpha-ketoglutarate or other readily metabolizable compounds. Such a supplement also converted the noncoordinate induction of this enzyme and pipecolate oxidase, both of the D-lysine pathway, to coordinacy. However, this effect was not observed if the enzyme pair was from different pathways of lysine metabolism in this organism (i.e., the D- and L-lysine pathways).
mesh_terms: D003470:Culture Media; D004790:Enzyme Induction; D007656:Ketoglutaric Acids / Q000494:pharmacology; D007700:Kinetics; D008239:Lysine / Q000378:metabolism*; D008670:Metals / Q000494:pharmacology; D008970:Molecular Weight; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000096:biosynthesis / Q000302:isolation & purification / Q000378:metabolism*; D011549:Pseudomonas / Q000201:enzymology*; D013237:Stereoisomerism
chemical_list: D003470:Culture Media; D007656:Ketoglutaric Acids; D008670:Metals; D000587:Oxidoreductases Acting on CH-NH Group Donors; C032772:1,2-didehydropipecolate reductase; C032771:L-pipecolate dehydrogenase; D008239:Lysine